Description : | Nickel sulphate is extensively used in electroplating, organic chemical synthesis, metal coloring, dye mordant, manufacturing other nickel salts, Ni-Cd battery. But resources of Nickel are dwindling day by day. Nickel catalysts used in various operations become spent after several cycle of use, for which a very simple and innovative process is developed at NML for recovery of nickel. The processing step consists of direct acid leaching in presence of a promoter followed by impurity removal to produce nickel salt/metal. The novelty of the process is that, it gives very high nickel recovery (99%) under the moderate conditions in presence of a little quantity of a promoter without which it is found to be very poor even at higher temperature and acid concentration. The process requires only little excess to the stoichiometric amount of acid for almost complete dissolution of nickel at moderate leaching temperature. It requires less amount of alkali in the purification step and generates less amount of sludge. The process gives very high recovery of nickel. |